1. Field of Invention
This invention relates to an apparatus for maintaining biological samples. The apparatus is particularly suited for transporting or storing adherent material including cell cultures. Additionally, the apparatus is useful for isolating and culturing microorganisms.
Historically, methods for culture confirmation testing, including isolation and identification of a microorganism, require inoculation of cell cultures with patient specimens and incubation to allow growth of the microorganism. Thereafter, the microorganism is detected using a variety of methods including observation of cytopathic effect and microorganism antigen specific confirmation tests. Cell cultures used in such procedures may be adherent, that is, grown attached directly to a support. Such supports include those integral with the container, for example the interior walls of a containing vessel, such as a tube, a microtiter plate, a vial, or the like. Supports also include microscope slides or coverslips, or the like which are not integral with the container.
In those instances where adherent material is stored or transported, it is important to do so without damaging the material. In some cases the support, such as a coverslip, is coated with adherent material and placed in a container which is filled with fluid, for example, cell culture medium. It is important to maintain contact between the adherent material and the fluid to ensure that the material remains viable. It is, therefore, important to maintain a solid fluid column in the containers because during shipment or storage the containers may be tipped or inverted for long periods of time. If a solid column of fluid is not maintained, it is necessary to ensure that containers having biological material on the walls or on a support such as a slide or coverslip are maintained in an upright position.
Additionally, vials used in the past for snipping or storing biological samples lacked a mechanism to ensure that a non-integral support contained therein would retain its original orientation during transportation or storage. If such a support is flipped over so that the adherent material is face down, subsequent procedures, for example an inoculation procedure, are impaired.
A second problem area relates to the handling of a seeded support, that is a support on which biological material is deposited, during procedures such as isolation and culturing biological samples on the seeded material. For example, prior to fixation, some systems require removal of the seeded support from the container in which it has been transported or stored. Such manipulation may involve handling infectious material prior to fixation and, therefore, may result in health hazards. Further, in instances where it is necessary to remove a seeded support from the container to stain the biological material, e.g., the cells, the reagent often flows off of the surface of the support, requiring additional reagent and time to complete the staining procedure. Additionally, if the support is stained after removal from the container, special attention must be given to staining the support evenly. Uneven coverage of the surface of the support causes diminution of staining intensity on poorly covered areas and a "drying edge" artifact on the adherent material. Furthermore, if the support is stained outside of the container, the support is rinsed by immersing it in a waterbath. This procedure requires handling the support with forceps and dipping it into the waterbath. During this procedure, there is a risk that the support will be broken or the adherent material will be damaged.
A support, such as a coverslip, coated with an adherent cell culture is generally removed from a container, such as a tube or vial, by using a bent needle to dislodge the support from the bottom of the container. This task is difficult and is made even more difficult by the presence of fluid beneath the support. After the support is dislodged from the bottom of the container, it is generally removed from the container with a pair of forceps and mounted onto a microscope slide for observation. This process requires skill and considerable dexterity. There is a high risk that the support will be broken or the adherent cell culture will be damaged during the removal procedures.
A cell culturing system called the "Gencell System" has been used for transporting biological samples. The system consists of a cap, a vial and two plastic pieces that are insertable into the vial. One of the insertable plastic pieces is designed to support a coverslip. It is necessary to manually manipulate the coverslip with a forceps to remove it from the insertable pieces. Because the position of the coverslip on the insertable pieces, the coverslip is often removed from the vial prior to staining to economize on reagent. Relatively large volumes of reagent must be used to evenly stain the coverslip if it is not removed from the vial.
There is need, therefore, for an apparatus that will maintain contact between a fluid medium and a support coated with adherent material even if the container is tipped or inverted for long periods of time. In addition, there is need for an apparatus wherein a support being transported in that apparatus will retain its original orientation during shipment. Further, there is need for an apparatus that is adapted for removing a support from it without the use of an instrument, such as a needle or forceps.
2. Description of the Prior Art
U.S. Pat. Nos. 2,665,690; 4,065,358; 4,470,505; 4,342,724 and 3,615,222 disclose multi-compartment containers. Containers and closures are disclosed in U.S. Pat. Nos. 3,432,066; 3,540,612 and 3,592,349. U.S. Pat. Nos. 4,546,085 and 4,321,330 disclose culturing devices. Various closures are disclosed in U.S. Pat. Nos. 3,005,564; 3,164,279; 3,223,269; 3,297,184; 3,370,732; 3,991,895 and 4,094,429.